The persistence of interest engagement was longitudinally studied with two different interest objects and two different states of interest development. Subjects with definite interest in microcomputers (n=7), with high interest in playing guitar (n=7), and with some interest, not well-developed, in computers (n=10) were interviewed initially and asked to record their internal processes and emotional states in subsequent logged task engagements. High persistent interest engagements between the person and the object were characterized by pleasant feelings, a high degree of absorption, an appreciation of the difficulties as not too easy and not too hard, and gains in proficiency. Sample sizes and numbers of interest engagements were not sufficient to indicate more than these general conclusions. (SLD)